Offset preventing mechanism



Ill

2 Sheets-Sheet l A. K. TAYLOR OFFSET PREVENTING MECHANISM Filed Dec. 7, 1955 April 27, 1937.

April 27, 1937.

A. K. TAYLOR OFFSET PREVENTXNG MECHANISM Filed Dec. 7, 1935 2 sneet s-sneet 2 I Patented Apr. 27, 1937 WE eras P'E'ENE' @FFHCE ()FFSET PREVENTING IHECHANISM Application December 7, 1935, Serial No. 53,329

6 Claims.

This invention relates to a device for spraying an anti-oifset liquid onto sheets as they come from the printing press to prevent ofiset, smearing or sticking together of the sheets on delivery. Slipsheeting and the treating of inks to prevent ofiset have not generally proved so satisfactory as spraying a liquid, which may be composed of a volatile element together with a gum like substance, upon the sheet as the freshly printed sheet comes from the press. The volatile element quickly evaporates leaving small invisible particles of the gum which prevent the succeeding sheets from coming in contact with the preceding sheets, and therefore offset and smudging are prevented.

From the spraying devices now commonly used the crust or solidified portions of the liquid accumulate on various parts of the press mechanism with the attendant risk of particles falling on the inking rollers and making their way to the form, tending to fill up same, making frequent wash ups necessary. Likewise with those now in usea larger particle than intended of the solution sometimes drops upon the sheet and this particle not drying as quickly as required causes two sheets of paper to adhere one to the other and usually ruins both. Very complex mechanism has been proposed to collect the atomized liquid which might not strike the sheets and draw it from the machine but these mechanisms are so complex and expensive that only few can afford them. Even with these mechanisms drops of the liquid often fall upon the sheet.

It has been observed that where the ordinary spray is in use the whole atmosphere around the press is that of a heavy fog and although the atomized liquid may not be injurious to health, its falling around the machine fouls up the same and ultimately causes considerable trouble.

This invention intends to do away with all of these drawbacks of the ordinary spraying apparatus and the objects thereof are to produce a spraying device wherein no large particles are allowed to reach the sheets as they are delivered from the press and wherein the spray not falling upon the sheets is absorbed and evaporated and not allowed to pass to other parts of the machine and to the surrounding atmosphere and wherein the spray is confined to the exact location of the sheets as they pass under the spraying device. Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings in which:

Figure 1 is a side elevation of a printing press delivery mechanism showing the invention thereabove.

Figure 2 is an end elevation of the same. Similar numerals refer to similar parts throughout the views. 5

The press delivers sheets 6 to tapes I passing around rollers 2 on shafts which are supported in the sides 4 of the delivery mechanism 3. As shown this mechanism is supported on stands 5 extending to the floor.

The printed sheets 6 are received on the mechanism from the printing press, not shown, with their printed sides up, the sheets pass successively' along the tapes I so that the upper face of each sheet is exposed completely in passing 15 along the tapes. Sprayers or atomizers I are supported on horizontally slidable rods 8 mount ed in vertically adjustable stands 9 on each side of the machine. Each sprayer has a pair of flexible hose l0 leading to the same, one carrying air and the other carrying the liquid to be 20 sprayed on the sheets. The mixture of air and liquid can be adjusted at the will of the operator and such mechanism is old in the art and forms no part in this invention.

On each side of the sprayers as the sheet 25 passes under the same is mounted an absorbent belt, the one farthest from the printing press being H and the one nearest the printing press being 82. These absorbent belts are mounted on rollers :3, l4 and. l5, l6 respectively. All the rollers are mounted in a stand I l which has legs extending to the floor. Both lower rollers l3 and I5 are placed in proximity to the sheets as they pass along the delivery tapes I and belt H is mounted upon an angle so that the lower roller l3 supporting the same is under the orifices of the sprayers i. In starting the sprayers, or at any other time, should a larger quantity of the liquid than desired pass from the sprayers 40 the same would fall by gravity upon the belt ll instead of upon the sheet as heretofore. Air ducts l8, one on each side of the sprayers, pass substantially parallel to the belts H and I2 and air blown therefore blows the spray downwardly upon the sheets. The pressure in these air ducts is sufiicient to blow the atomized spray but not sufiicient to blow large particles of the liquid upon the sheets. These air ducts l8 are supported on cross members E9 of the stand l1 and receive their air under pressure through ducts 20 from a conventional blower, not shown.

Belts II and I2 are driven so that the surface struck by the spray moves in a direction opposite to the spray, that is, the inwardly dier I3 is driven by a step-by-step motion from ratchet 2i attached to the shaft. on which the passing to the sheet coated with very ,which prevent offset in the next handling of the sheet.

roller is mounted and this ratchet 2| is moved by pawl 22 mounted on arm 23. The arm has a spring thereon holding the pawl in engaging relation with ratchet wheel 2!. A spring-attached at one end to one of the sides i of the press delivery mechanism 3 and attached at its other end to the arm 23 tends to pull the arm always ,toward the right as shown in Figure 1. A stop'25 likewise mounted on one of the sides 4 limits the backward movement of the arm under the influence of this spring. .In such presses there are nearly always reciprocating parts extending longitudinally to the delivery mechanism. These reciprocating members usually have a long stroke and one such member is shown at 26 having a roller 21 mounted thereon. The position of the roller on the reciprocating member may be varied by adjustment. This roller 21 strikes arm 23 and moves the same to the left as shown in Figure 1 thereby imparting motion to the .pawl 22 and ratchet wheel 2i and rotating belt II by a step-by-step motion. By means of crossed belt 28, belt I2 is driven in a direction opposite to that of belt H, the length of the stroke of the arm 23 thereby varying the amount of turn-up of each belt H and \I2. Curtains 29 extend from the cross members IQ of the framework or stand I! and these curtains are preferably weighted at their lower ends so that they will extend within the longitudinal sides 4 of the delivering mechanism and prevent the spread of the spray beyond the sheets.

The absorbent belts take up the spray not and prevent it from spreading over the machine-and into the room. As they pass upwardly the volatile portions of the liquid evaporate and the solid portions are sufficiently dried so as not to drop off when the belt surfaces pass over the top rollers. On two sides of the nozzles the belts restrict the spray and on the other two sides the curtains restrict the spray thereby making a complete surrounding of the spray as it passes from the sprayers to the sheet and as the sheets pass from under the sprayers and belts H I and I2 the same are fine particles of the dried gum A number of changes and variations may be made in the structure above described and shown in the accompanying drawings without departing from the .spirit and scope of the invention:

I claim:

1. In combination, mechanism for receiving freshly printed sheets in succession from a press with printed faces up, a sprayer above said sheets to spray anti-offset liquid upon the passing sheets, a pair of absorbent endless belts each being mounted on a pair of spaced rollers, one belt being on each side of said sprayer and said rollers extending substantially at right angles to the direction of movement of said sheets, one rolle of each belt being in proximity to the moving heets and the other roller of each belt extending above the spread of the spray from said sprayer and'means to drive said belts whereby the spray is confined and directed upon the sheets and the absorbent belts constantly present an adhering surface for spray striking the same.

2. In combination, mechanism forv receiving freshly printed sheets in succession from a press with printed faces up, a p y r a ve said Sh Q S to spray anti-offset liquid upon the passing sheets, a pair of absorbent endless belts each being mounted on a pair of spaced rollers, one belt being on each side of said sprayer and said rollers extending substantially at right angles to the direction of movement of said sheets, one roller of each belt being in proximity to the moving sheets and the other roller of each belt extending above the spread of the spray from said sprayer, the surface facing the sprayer of one of saidbelts being inclined and passing under the spraying orifice of said sprayer, and means to drive said belts whereby the spray is confined and directed upon the sheets and the absorbent belts constantly present an adhering i surface for spray striking the same.

3. In combination, mechanism for receiving freshly printed sheets in succession from a press with printed faces up, a sprayer above said sheets to spray anti-offset liquid upon the passing sheets, a pair of absorbent endless belts each being mounted on a pair of spaced rollers, one belt being on each side of said sprayer and said rollers extending substantially at right angles to the direction of movement of said sheets, one roller of each belt being in proximity to the moving sheets and the other roller of each belt extending above the spread 01 the spray from said sprayer and means to drive said belts so that their surfaces facing the spray move in a direction opposite to that of the spray whereby the spray is confined and directed upon the sheets and the absorbent belts constantly present an adhering surface for spray striking the same.

4. In combination, mechanism for receiving freshly printed sheets in succession from a press with printed faces up, a sprayer above said sheets to spray anti-offset liquid upon the passing sheets, a pair of absorbent endless belts each being mounted on a. pair of spaced rollers, one belt being on each side of said sprayer and said rollers extending substantially at right angles to the direction of movement of said sheets, one roller of each belt being in proximity'to the moving sheets and the other roller of each belt extending above the spread of the spray from said sprayer and means to drive said belts and means at the sides of said belts to confine the spray at the sides of the sheets whereby the spray is confined and directed upon the sheets and the absorbent belts constantly present an adhering surface for spray striking the same.

5. In combination, mechanism for receiving freshly printed sheets in succession from a press with printed faces up, a sprayer above said sheets to spray anti-offset liquid upon the passing sheets, a pair of absorbent endless belts each being mounted on a pair of spaced rollers, one belt being on each side of said sprayer and said rollers extending substantially at right angles to the direction of movement of said sheets, one

roller of each belt being in proximity to the moving sheets and the other roller of each belt extending above the spread of the spray from said sprayer and means to drive said belts and means extending adjacent to the surfaces-of said belts and on each side of said sprayers to direct currents of air downwardlyupon the sheets whereby the spray is confined and directed upon the sheets and the absorbent belts constantly present anadhering surface for spray striking the same.

6. In combination, mechanism for receiving freshly printed sheets in succession from a press with printed faces up, a sprayer above said sheets to spray a quickly drying anti-oiiset liquid upon I the passing sheets, an absorbent belt adjacent one side of said sprayer mounted on a pair of spaced rollers, one roller being in proximity to the moving sheets and the other extending above the spread of the spray from said sprayer, said rollers extending substantially at right angles to the direction of movement of said sheets, the surface of said belt facing the sprayer being inon said belt may dry on the same and not pass to 5 the sheets.

ARTHUR K. TAYLOR. 

